The latest update is built on pre-release version of the Gecko 1.9.1, Mozilla announced, and is mainly aimed at developers and testers. As usual, early adopters looking to play around with the browser are sure to install it as well.

According to its developer, the Shiretoko Alpha 2 introduces the following features:
– support for the HTML 5 <video> element
– initial support for web worker threads
– drag and drop tabs between browser windows
– new selector to create areas of Aero-style “glass” in XUL
– support for CSS 2.1 properties: ::before and ::after, and white-space:pre-line
– support for CSS 3 properties: -moz-border-image, word-wrap: break-word, text-shadow, box-shadow and column-rule
– performance improvements and new preference values for color management profile support

The Tracemonkey JavaScript engine is not part of this offer. The developer announced that this one is undergoing an update process and it’s only available as a separate download.

The beta version of the browser is expected to be completed by the end of September and, if all goes right for Mozilla, the final release candidate should appear on the download servers in October.